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Q3) Furnace overall wall (Area- 1 m2) is 200 mm thick. The furnace wall is made up of

an inner layer of fire brick (- 0.85 W/m "C) and covered with a layer of insulation (k

0.20 W/m. C). The furnace operates at a temperature of 1000C and the ambica

temperature is 30°C. Determine the thickness of fire brick and insulation which gives

minimum heat loss and calculate the heat loss presuming that insulating material ha a

maximum temperature at inlet is 933°C. (4 marks)

T=30°C

L200mm

Insulation

Brick

110000